1. Field of the Invention
This invention is directed to novel processes for preparing derivatives of glycopeptide antibiotics. More specifically, this invention is directed to multi-step processes for preparing phosphonate derivatives of glycopeptide antibiotics having an amino-containing side chain, the first two steps being conducted in a single reaction vessel without isolation of the intermediate reaction products.
2. Background
Glycopeptides (e.g. dalbaheptides) are a well-known class of antibiotics produced by various microorganisms (see Glycopeptide Antibiotics, edited by R. Nagarajan, Marcel Dekker, Inc. New York (1994)). Many synthetic derivatives of such glycopeptides are also known in the art and these derivatives are typically reported to have improved properties relative to the naturally-occurring glycopeptides, including enhanced antibacterial activity. For example, U.S. patent application Ser. No. 09/847,042, filed May 1, 2001, describes various glycopeptide phosphonate derivatives, some of which contain an amino-containing side chain. Such phosphate derivatives are particularly useful as antibiotics for treating gram-positive infections.
Accordingly, a need exists for new efficient processes which are useful for preparing phosphonate derivatives of glycopeptide antibiotics having an amino-containing side chain.